Planetary grinding mill



Sept. 22, 1970 c. H. WILKINSON, JR

PLANETARY GRINDING MILL 4 Sheets-Sheet l Filed May 8, 1968 Sept. 22,1970 c. H. WILKINSON, JR 3,529,730

PLANETARY GRINDING MILL Filed May 8, 1968 4 Sheefcs-Sheet 2 CECIL H.WILKINSON ,JR.

VIII/IIII/II/IIII/IIIII/IIIIIIIIIIIIIIIIIIII/l Z t drill/fill!!!l/Il/drflllaa WWW I u I r. I. I 1 I I I I I I I I I a If/IIIIIIIII'I'IIIIIIIII ATTORNEY Sept. 22, 1970 c. H. WILKINSON, JR

PLANETARY GRINDING MILL Filed May 8, 1968 4 Sheets5heet 5 FIG-9.

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IIIIIHI EIIIITIITIHIIIII INVENTOR CECIL H. WlLKl NSONJR.

ATTORNEY p 1970 c. H. WILKINSON, JR 3,529,780

PLANETARY GRINDING MILL 4 Sheets-Sheet 4.

Filed May 8, 1968 H5 FIG.H.

W R w I J N N R 3 7 EN 0 9. $3 8 8 mw w m W W I m m 4 o 6. 1 4 m m m 8 WH X 5 I h IO {MEI-.1 L 6 4 m if C 9 C 7 w vm m Q i W H 2 A \QWM /8 H B W4 w l D o 7 5 l. 5 l .l 9 9 2 I m. 9 3 I m, m M W n 6 l 2 u I l H 8 O 5l m w W O O .I no u /4 m m l l 8 I w M W. W 3 w a United States Patent O3,529,780 PLANETARY GRINDING MILL Cecil H. Wilkinson, Jr., 1969 East21st St. South, Salt Lake City, Utah 84106 Filed May 8, 1968, Ser. No.727,549 Int. Cl. B02c 19/00 US. Cl. 241134 4 Claims ABSTRACT OF THEDISCLOSURE A continuously fed planetary grinding mill which is capableof operating at a high rate of speed due to the fact that the grindingaction is accomplished by centrifugal force and is not dependent upongravity. The grinding chamber of the mill has an attached dischargecompartrnent, which chamber and compartment revolve about a main axis ofthe mill but do not revolve about an axis common thereto, so thatintermittent discharge from an outlet port of the discharge compartmentcan be controlled.

BACKGROUND OF THE INVENTION This invention relates to the art ofplanetary grinding mills.

The prior art discloses planetary type grinding mills operating eitherabout a horizontal axis or a vertical axis and which are either of thecontinuous feed type or the batch operation type, and which usuallyrequire two motors or power sources.

SUMMARY The primary object of the present invention is to provide agrinding mill requiring only one motor or power source for a planetarytype operation and which is capable of operating at very high speeds dueto the fact that the grinding is accomplished by centrifugal forcerather than by gravity.

A particular object of the invention is to provide a planetary grindingmill including a grinding chamber and a discharge compartment having acommon axis, and which are supported for rotation about a maindriveshaft of the mill and maintained against rotation about the axis ofthe grinding chamber and discharge compartment, whereby a discharge portof the discharge compartment moves toward and away from the maindriveshaft during each revolution thereof and discharges only when in aposition remote from the driveshaft.

Accordingly, a further object of the invention is to provide a planetarygrinding mill wherein the discharge point may be located in any desiredposition about the axis of rotation of the mill.

Another object of the invention is to provide a plan etary grinding millthe outlet of the grinding chamber of which is of a larger diameter thanthe inlet to said chamber, whereby a cross current flow is developed forcarrying particles of solids toward the outlet.

A further object of the invention is to provide a grinding mill thedischarge from which is thrown tangentially toward and caught in ahopper.

A further object of the invention is to provide a planetary grindingmill the main axis of which may be disposed horizontally, vertically orat an incline.

BRIEF DESCRIPTION OF THE DRAWINGS Various other objects and advantagesof the invention will hereinafter become more fully apparent from thefollowing description of the drawings, illustrating presently preferredembodiments thereof, and wherein:

FIG. 1 is a side elevational view, partly broken away, of one embodimentof the planetary grinding mill;

Patented Sept. 22, 1970 FIG. 2 is an end elevational view, partly brokenaway, looking from left to right of FIG. 1;

FIG. 3 is a fragmentary cross sectional view taken substantially along aplane as indicated by the line 3-3 of FIG. 1, and partiallydiagrammatic;

FIG. 4 is an enlarged fragmentary longitudinal sectional view of aportion of the grinding mill;

FIG. 5 is a fragmentary sectional view thereof taken substantially alonga plane as indicated by the line 5--5 of FIG. 4;

FIG. 6 is a fragmentary cross sectional view taken substantially along aplane as indicated by the line 6--6 of FIG. 4;

FIG. 7 is a fragmentary longitudinal sectional view of a slightmodification of the grinding mill of FIGS. 1 to 6;

FIG. 8 is a substantially central longitudinal sectional view, partlybroken away, of another embodiment of the planetary grinding mill;

FIG. 9 is a fragmentary cross sectional view thereof, partlydiagrammatic, taken substantially along a plane as indicated by the line9-9 of FIG. 8 but with certain of the parts disposed in differentpositions than as seen in FIG. 8;

FIG. 10 is a side elevational view of a third embodiment of theplanetary grinding mill, partly broken away;

FIG. 11 is an enlarged longitudinal vertical sectional view thereof,partly in side elevation and partly broken away;

FIG. 12 is an enlarged horizontal sectional view taken substantiallyalong a plane as indicated by the line 1212 of FIG. 11; and

FIG. 13 is a fragmentary vertical sectional view of a slightly modifiedembodiment of the grinding mill of FIGS. 10* to 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more specifically tothe drawings, and first with reference to FIGS. 1 through 6, theplanetary grinding mill as disclosed therein and designated generally 15includes an elevated platform or base 16 which may be supported in anysuitable manner as by depending legs 17. Two posts or uprights 18 and 19are fixed to and rise from the base 16 and provide supports for bearings20 which align with one another to provide journals for a shaft 21 whichis rotatably supported thereby above and substantially parallel to theplane of the base 16. A conventional electric motor or other suitablepower source 22 is supported by and fixed to the base 16 and isconnected to and drives the shaft 21 through a V-belt and pulley drive23. Collars 24 are secured to the shaft 21 and straddle the bearing 20of the post 18 for retaining the shaft 21 against sliding movement inthe bearings 20.

A frame 25 is fixed to the shaft 21, between and spaced from the posts18 and 19 and bearings 20, and has end portions 26 and 27 projectingradially from the shaft 21 in opposite directions. The end portion 26includes spaced apart, substantially parallel and rigidly connected arms28 and 29 provided with aligned bearings 30 and 31, respectively, inwhich are journalled trunnions 32 and 33, respectively, which projectfrom the ends of a grinding unit 34 which is rotatably mounted betweenthe arms 28 and 29.

The grinding unit 34 includes a cylindrical grinding chamber 35 havingan end wall 36 which is detachably secured to one end thereof byfastenings 37. The trunnion 33 constitutes an outwardly projectingcentral portion of the end wall 36.

The grinding unit 34 additionally includes a cylindrical dischargecompartment 38 of smaller diameter than the 3 grinding chamber and whichprojects from the other end wall 39 of the chamber 35. The chamber 35and compartments 38 are coaxially disposed relative to one another andthe wall 39 constitutes an end wall of each and is provided with acentrally disposed opening 48 which connects the chamber 35 andcompartment 38. The trunnion 32 is fixed to and projects outwardly fromthe other end wall 41 of the compartment 38. The cylindrical wall 42 ofthe compartment 38 is provided with a discharge port 43, as best seen inFIGS. 4 and 6, which is substantially smaller than the opening 40,which, in turn, is of a diameter substantially less than the diameter ofthe wall 42. A baffle 44 extends across the compartment 38. between thewalls 39 and 41 and is disposed between the opening and port 43. Thebaffle 44 is of a circumferential length to extend beyond tangentsthrough the opening 40 and port 43 for a purpose which will hereinafterbe described.

As seen in FIG. 4, a sprocket wheel 45 is secured immovably to the post19 by a pin 46 having portions of noncircular cross section engaging insaid post and in the sprocket wheel. The sprocket wheel 45 has anopening 47 disposed around and spaced from a part of the shaft 21. Asprocket wheel 48 is fixed to the trunnion 32, between the wall 41 andbearing 30, and an endless chain 49 is trained around the sprocketwheels 45 and 48, which are of the same size.

The other end portion 27 of the frame comprises spaced apartsubstantially parallel arms 50 between the outer ends of which issecured a counterweight 51 for counterbalancing the end portion 26 ofthe frame and the parts supported thereby.

A feed hopper 52 is provided with a downwardly inclined chute 53 whichis supported by a bracket 54 on one side of the post 18. A feed supplyduct 55 is disposed on and connected to the outer side of the frame arm29 and has an outlet port 56, FIG. 4, mounted in an opening 57 of thearm 29 and disposed to discharge into the trunnion 33 which is hollow toprovide the inlet port of the grinding chamber 35. An outer wall 58 ofthe duct 55 has an inlet opening 59 which is disposed around and spacedfrom a part of the shaft 21 and from the outlet end of the chute 53which discharges into the duct 55.

A discharge hopper 60 is mounted in and extends through an opening 61 ofthe base 16, FIG. 3, and has an elongated open upper inlet end 62 whichextends nearly concentrically around the lower portion of the path ofrotation of the grinding unit 34 and which is curved to substantiallyconform to the curvature of said path. The

hopper 60 has an outlet port 63 at its lower end through which theground material may be discharged into any suitable container, notshown, or a conduit leading therefrom.

In the embodiment of the grinding mill 15 as illustrated in FIGS. 1 to6, the shaft 21 is driven at a high rpm. by

the motor 22 through the belt and pulley drive 23 and revolvesclockwise, as seen in FIG. 3. The product to be ground, usually a slurrytogether with a fluid, is fed by gravity from the hopper 52 through thechute 53 into the duct 55 from which it is conveyed by centrifugal forceto and through the duct outlet 56 and into the grinding chamber 35through its inlet 33. If the grinding is to be accomplished with balls,these may be added with the feed. The product to be ground is urged bycentrifugal force against the portion of the cylindrical wall of thechamber 35 disposed most remote from the shaft 21 and as such chamberdoes not revolve about its own axis 32, 33, as will hereinafter bedescribed, tumbling of the product being ground will occur in thechamber 35 to effect the grinding operation. It will be apparent thatthe higher the speed of rotation of said chamber the better the grindingoperation which will result. As the outlet 40 of the chamber 35 islarger than its inlet 33, a cross current flow develops which will carrythe particles of solids toward the outlet 40. The slurry overflowingfrom the grinding chamber 35 through the outlet 40 is caught in thedischarge compartment 38 and accumulates for one revolution of themachine.

Since the sprocket wheel 45 does not revolve the chain is driven aroundsaid sprocket wheel and drives the sprocket wheel 48 to thus prevent thegrinding unit 34 from revolving in its bearings 30 and 31 While saidunit revolves with the frame 25 around the shaft 21. For this reason theproduct being ground tumbles about the inner surface of the wall of thechamber 35 and also about the inner surface of the wall 42 of thedischarge compartment.

FIG. 3, in full and dotted lines, shows the location of the dischargeport 43 during the entire circuit of travel of the discharge compartment38 concentrically around the shaft 21. in the topmost full line positionof the compartment 38 the discharge port is at a three oclock positionand the ground product 60 is located in the topmost part of the chamber38 and spaced from the port 43. As the chamber 38 travels clockwise fromits full line position to its initial dotted line position atapproximately four oclock with respect to the shaft 21, the dischargeport which is in the same vertical plane as the hopper inlet mouth 62,has assumed a position more remote from the shaft 21 than in its initialfull line position, and the product 64 has tumbled around thecompartment 38 until its leading edge has reached the discharge port 43,so that it will begin to be discharged by centrifugal force into thehopper mouth 62 and in a direction nearly tangentially of thecompartment 38 or toward the lower left hand portion of said hopper, asseen in FIG. 3. The dis charge of the product 64 from the port 43 willcontinue until the compartment 38 approaches its next position clockwisewith respect to the shaft 21, at approximately seven oclock, at whichtime the port 43 will have moved closer to the shaft 21 and the product64 will tumble to below said port so that no further discharge willoccur. Similarly, the product 64 will be in the part of the compartment38 remote from the port 43 as said compartment reaches its nextapproximately ten oclock position, in which position the port 43 is inclose proximity to the shaft 21. Thus, the discharge which occurs duringeach revolution of the unit 34 about the shaft 21 is an intermittentdischarge controlled so as to occur during the same part of eachrevolution and which can be varied by varying the initial position ofthe discharge port in the full line position of the compartment 38 if itis desired to locate the hopper 60 in a different position from thatshown. The baffle 44 prevents the product 64 from being discharged bycentrifugal force directly from the grinding chamber outlet 40 to thedischarge port 43, to assure that the product will travel one completerevolution while in the discharge compartment.

FIG. 7 illustrates a slight modification of the grinding mill 15 andwherein a hollow container 65 containing a weight in the form of a fluidmaterial 66 is mounted between the arms 50 in lieu of the solidcounterweight 51.

FIGS. 8 and 9 illustrate a slightly different embodiment of the grindingmill, designated generally 67, and which includes the parts 16 to 24inclusive, corresponding to the parts of FIGS. 1 to 6 bearing the samereference numerals. A frame 68, which comprises spaced arms 69 and 70which are fixed intermediate of their ends to the shaft 21, replaces theframe 25. The arm 69 has a bearing 71 adjacent each end thereof and thearm 70 has a bearing 72 adjacent each of its ends. The bearings 71 and72 align with one another and correspond with the bearings 30 and 31,respectively.

Two grinding units 34' are supported in the frame 68 each being mountedin a bearing 71 and a bearing 72 thereof, in the same manner that thegrinding unit 34 of FIGS. 1 to 6 is rotatably mounted in the bearings 30and 31. The two grinding units 34 of FIGS. 8 and 9 counterbalance oneanother so that the counterweight is eliminated.

In lieu of the sprocket wheels 45 and 48 and the chain 49, a sun gear 73is secured to the post 19 by the pin 46 and is disposed between saidpost and the frame arm 69. The sun gear 73 has a central opening 74disposed around and spaced from a part of the shaft 21. A gear 75 issecured to each trunnion 32 of the grinding units 34. The gears 73 and75 are the same diameter and have the same number of teeth. Smallerintermediate gears 76 mesh with the sun gear 73 and the gears 75 and arejournaled on stub shafts 77 which are supported by and extend outwardlyfrom the frame arms 79 between its bearings 71 and the shaft 21.

A feed supply duct 78 is secured to the outerside of the arm 70 and hasinwardly directed discharge ports 79 at the ends thereof mounted in andextending through openings 80 of the arm 70 for discharge into thehollow trunnions 33'. The intermediate portion of the outer wall 81 ofthe duct 78 has an inlet opening 82 corresponding to the duct opening 59and which is disposed around a part of the shaft 21 and the outlet endof the chute 53. The hopper 52, chute 53 and its support 54 correspondwith the like numbered parts of FIGS. 1 to 6 and are mounted in the samemanner. The grinding mill 67 also includes the same hopper 60 mounted inthe same manner in the base 16 and the mouth 62 of which is disposed inthe same manner with respect to the discharge ports 43' of the twogrinding units 34', as in FIGS. 1 to 6.

The grinding units 34 differ from the grinding unit 34 in that thegrinding chamber 35' and discharge compartment 38' thereof are of thesame diameter.

The operation of the grinding mill 67 corresponds with the operation ofthe grinding mill 15, as heretofore described in detail, with each ofthe grinding units 34 discharging during each revolution of the shaft 21and frame 68, in the same manner that the single grinding unit 34 ofFIGS. 1 to 6 discharges. The gears 73, 76 and 75 perform the samefunction as the sprocket wheels 45 and 48 and chain 49 in causing theoutlet ports 43 to move toward and away from the shaft 21 and to assumean outermost position while each port is traveling along the hoppermouth 62 for discharging the product 64 into the hopper 60, asillustrated in full and dotted lines in FIG. 9, wherein the two grindingunits are shown in full line with the lower right hand one thereofcommencing to discharge into the hopper 60. The dotted line position ofthe grinding unit 34 in FIG. 9 shows the position that each grindingunit will assume during each complete circuit of its travel and afterthe discharge therefrom is completed. Baffies 44' function in the samemanner as baffie 44.

It will thus be seen that the grinding mills 15 and 67 are each of thecontinuous feed intermittently discharging type. It will also beapparent that by modifying the frame 68 three or more grinding units 34'could be utilized so long as the grinding units were arrangedsymmetrically around the shaft 21. The duct 78 would then be modified toprovide a duct passage discharging into each grinding unit inlet port.

FIGS. 10, 11 and 12 illustrate another embodiment of the grinding mill,designated generally 83, and which rotates about a vertical axis ratherthan an horizontal axis as in the grinding mills 15 and 67. The grindingmill 83 includes a frame 84 having a bottom or base portion 85, a topportion 86 and side portions 87 and 88 extending between and connectingthe ends of the portions 85 and 86. A main, vertically disposeddriveshaft 89 has its lower end journaled in an upwardly opening bearing90 of the base portion 85 and an intermediate portion journaled in abearing 91 of the frame member 86. A platform '92 is fixed to the upperend of the shaft 89 and disposed at a right angle thereto. Twocorresponding grinding units 93 are supported by the platform 92 bymeans of stub shafts 94 which extend downwardly through and arejournaled in bearings 95 of the platform 92. Each stub shaft has a largeupper portion or collar 96 which rests rotatably on the platform 92 forspacing the grinding units therefrom.

Each grinding unit 93 includes a cylindrical bottom chamber 97constituting the grinding chamber thereof and a cylindrical upperchamber constituting the discharge compartment 98. The parts 97 and 98have outwardly extending peripheral flanges 99 connected by fastenings100. A flat annular member 101 has its peripheral portion securedbetween the flanges 99 by the fastenings and has a central opening 102forming the outlet opening of the grinding chamber 97. A tube 103 has anupper portion secured in a flanged central opening 104 of the top wallof the discharge compartment 98. The tube 103 is preferably flaredtoward its lower end and said lower end extends axially into the opening102 and is of a substantially smaller diameter than said opening. Thedischarge compartment has a discharge port 105 in its cylindrical sidewall and a bafile 106 is disposed in the discharge compartment betweenthe port 105 and inlet 102 and bears the same relation to said port andinlet as the baffle 44 of the mill 15, as best seen in FIG. 12.

A post 107 is fixed to and extends upwardly from the platform 92 and isdisposed in axial alignment with the shaft 89 and directly between andspaced from the grinding units 93. The shaft 89 extends centrallythrough and is turnable in a sun gear 108 which is secured immovably tothe bearing '91 by a pin 109. The sun gear 108 is disposed between andmeshes with intermediate gears 110 which are journaled on stub shafts111 which depend from the platform 92. Gears 112 are secured to thelower ends of the stub shafts 94 and mesh with the intermediate gears110. The gears 112 are of the same diameters as the sun gear 108 and areof larger diameters than the gears 110. An upper portion of the sidemember 88 supports a feed hopper 113 having a downwardly inclined chute114 which discharges into an intermediate portion of a feed duct 115through an opening 116 thereof which is disposed around and spaced fromthe chute 114. The duct 115 has downwardly extending discharge ports 117at the ends thereof which open into the tubes 103. The duct 115 issupported by and rotates with the post 107.

A hopper 118 is mounted in an opening 119 in the upper portion of theside member 88 and is disposed in substantially an horizontal plane andhas a hopper mouth 120 of the same shape as the hopper mouth 62 which isdis posed in the plane of the discharge ports 105,.adjacent to andsubstantially concentrically around the circuit of travel of thedischarge compartments 98, as seen in FIG. 12. A conduit 121 leads fromthe hopper 118 to any suitable discharge point.

A conventional electric motor 122 is secured to the frame part 87 anddrives the shaft 89 by a belt and pulley drive 123, for revolving theplatform 92, the grinding units 93 and the duct 115 about the axis ofthe shaft 89. The gears 108, 110 and 112 function in the same manner asthe gears 73, 75 and 76 of the mill '67 and for the same purpose asheretofore described, so that the discharge port 105 of each unit 93will be remote from the post 107 as it passes across the hopper mouth120, to discharge into said mouth, and will be adjacent the post 107,when disposed remote from the hopper, as illustrated in FIGS. 11 and 12,and for the same reason as heretofore described in reference to themills 15 and 67.

The feed discharges by gravity from the chute 114 into the duct 115 andis conveyed therethrough by centrifugal force and discharged from theports 117 through the tubes 103 into the grinding chambers 97. Theground product overflows through the outlets 102 of the chambers 97 intothe discharge compartments 98.

FIG. 13 illustrates a slightly modified embodiment of the grinding mill84 and which differs therefrom in that the tubes 103 are omitted, theflanged openings 104 are replaced by enlarged openings 104' and thedischarge ports 117 of the duct 115' extend downwardly and outwardly atan incline through the openings 104' and the grinding chamber outlets102 and terminate slightly beneath the members 101. The construction andoperation of the 7 grinding mill 124 of FIG. 13 is otherwise the same asthat of the mill 84.

It will be readily apparent that the grinding mills 15 and 67 could bedisposed at an incline rather than with the axes of their driveshafts inan horizontal plane, and the grinding mills 84 and 124 could likewise bepositioned at an incline rather than with their main shafts disposedvertically.

The grinding may be accomplished autogenously, or with rods, balls orpebbles. However, rods would only be utilized when the axis of the mainshaft is nearly horizontal, as in FIGS. 1 to 9.

Various other modifications and changes are contemplated and may beresorted to, without departing from the function or scope of theinvention as hereinafter defined by the appended claims.

I claim as my invention:

1. A planetary grinding mill comprising a main shaft, means rotatablysupporting said shaft, drive means rotata'bly driving said shaft, aframe fixed to the shaft for rotation therewith, a cylindrical grindingunit, means rotatably mounting said grinding unit in said frame about anaxis radially spaced from and disposed parallel to the axis of saidshaft, said grinding unit including a cylindrical grinding chamber and acylindrical discharge compartment axially aligned with the grindingchamber, said grinding chamber having an opening constituting an outletthereof discharging into the discharge compartment and an inletdischarging axially into said chamber, means for supplying a product tobe ground to the grinding chamber inlet, said discharge compartmenthaving a discharge port opening radially therefrom, a hopper having amouth spaced outwardly from and opening toward a part of the circuit oftravel of said discharge compartment, means connecting said firstmentioned means to the grinding unit to prevent rotation of the grindingunit about its axis as it revolves with the frame about the axis of saidshaft for causing the product to be ground in the grinding chamber by atumbling action due to centrifugal force and to overflow therefromthrough said outlet into the discharge compartment, and for causing theground product to move around the discharge compartment and intoregistry with the discharge port as said port assumes a position remotefrom the axis of the shaft and facing the hopper mouth for discharge ofthe ground material into the hopper, and a baffle disposed in thedischarge compartment between the grinding chamber outlet and saiddischarge port and concentric thereto, said baffie having acircumferential length greater than the circumferential length of thedischarge port and less than the diameter of the grinding chamberoutlet.

2. A planetary grinding mill as in claim 1, said hopper mouth beingelongated in a direction substantially concentric to the circuit oftravel of the discharge compartment and being curved to substantiallyconform to the arc of said circuit of travel.

3. A planetary grinding mill as in claim 1, said inlet port of thegrinding chamber being smaller than and disposed remote from thegrinding chamber outlet.

4. A planetary grinding mill as in claim 1, said grinding chamber inletopening into the grinding chamber through the grinding chamber outlet,and said grinding chamber outlet constituting an annular space disposedaround said inlet.

References Cited UNITED STATES PATENTS 405,810 6/1889 Wegmann 241-175458,662 9/1891 Pendleton 241-175 569,828 10/1896 Herzfeld 2411751,144,272 6/1915 West 241137 1,309,212 7/1919 Marcy 241176 1,951,8233/1934 Eppers 24l137 2,021,671 11/1935 Skinner 241 2,818,220 12/1957Woody 241 FOREIGN PATENTS 390,998 10/1908 France. 436,534 10/1935 GreatBritain.

GERALD A. DOST, Primary Examiner US. Cl. X.R. 24117l, 175, 284

